Tag: FDIM

This year’s Four Days in May at the Dayton Hamvention was full of sights to see. One amazing little piece of amateur engineering was Rich Meiss, WB9LPU’s “QuadraBug”, a mechanical key in the spirit of the Vibroplex Bug, but with fully automatic keying of both dits and dahs. (A bug has automatic dits, but manual dahs.)

At this year’s Dayton Hamvention, I attended the Four Days In May QRP event put on by QRP-ARCI. A number of projects were on display, including this transceiver.

Carl Herbert, AA2JZ designed and built this 40m transceiver, drawing on the NW8020 as a source of inspiration. It uses NE602 mixers and two PIC microcontrollers, and includes a keyer and a frequency counter.

I was impressed by Carl’s tidy Manhattan-style assembly technique, in which small pieces of copperclad board (PCB material) are glued down and used as points to which wires and component leads are soldered. Most impressive is that he used the same technique for the chips. Carl must have a lot of patience to be able to position the little “nibbles” of copperclad at 0.1″ spacing to take the IC leads.

A few weeks ago, I went to the Dayton Hamvention and the accompanying QRP event, Four Days In May (FDIM). QRP-ARCI always puts on a good program for FDIM, with a full day conference on Thursday, the day before Hamvention opens, and evening events Thursday, Friday, and Saturday.

Among the evening events are a show-and-tell night and a building contest night. Show-and-tell is open to anyone to bring a QRP-related project to share, whether finished or work-in-progress. The building contest has had varying rules over the years, but this year it had several categories, including kit-built radios, scratch-built radios, and station accessories. Judging was by audience ballot.

I took some photos and notes from the evening events and will be sharing them over the next few weeks.

First up is HamOS. Rich Gordon KD0BJT and Brady AC0XR were demonstrating this Linux-based operating system and handing out CD-R’s as fast as they could burn them. HamOS is a GNU/Linux distribution focusing on ham radio, with a variety of radio applications pre-installed. I can’t find a download link for HamOS, but hopefully that will be rectified soon.

Rich was lucky enough to get the “BJT” (Bipolar Junction Transistor) acronym in his call — and it looks like it is sequentially assigned, not vanity!

Rich and Brady also produce the lowSWR podcast, to which I have just subscribed.